TAMWORTH, N.H. - The first and most striking sensation is the howling - a primal cacophony reverberating across frozen Lake Chocorua in the morning chill.

But even a novice quickly picks up on the canine vibe: These are not calls of alarm or intimidation. The 63 teams of Huskies and mixed breeds gathered for the oldest continuous sled dog race in the Northeast are creatures clearly relishing a routine.

Coiled with anticipation, each frenzied pack awaits its turn in the starting chute as the countdown begins for the six-dog pro class time trials. Four assistants per team - one to hold each coupling of harnessed Huskies while the fourth braces the sled - restrain the racers while the driver stomps on a claw brake. The yelping peaks as the timer ticks to zero, then the driver deftly shuffles off the brake and goes into a furious skating motion.

The pack surges forward, launching an explosive kickback of snow, and all barking immediately quiets as the team hits full stride four jumps off the line.

"It's like - whoosh," said Martha Heckman of Kingston, N.H. She and her husband, Bob, have been racing sled dogs for 42 years, and Martha still has difficulty articulating that incredible feeling of being whisked off the line by a well-trained team.

Sled dog racing has a long history in the Northeast, but the sport remains under the radar. The New England Sled Dog Club, which sanctions the Tamworth race, was founded in 1924 after a local adventurer traveled to the Yukon during the gold rush and decided to introduce sled dog rides at his Wonalancet, N.H., inn. As popularity grew, point-to-point races between rural towns began to emerge.

In 1932, Wonalancet was the site of Olympic elimination trials when the Winter Games at Lake Placid, N.Y., staged sled dog racing as a demonstration event.

'It's a lifestyle'

Dog racing never caught on as an Olympic sport. Although it has maintained a steady club level of competition, the exact state of the sport is tough to pinpoint: With strongholds only in northern New England, Minnesota, Alaska, and Canada, sled dogging is extremely provincial and weather-dependent. Thus, few newcomers get exposed to it, and those who want to race must make sizable commitments of time and money to care for their own kennel.

Yet on the other hand, judging by the outgoing, friendly nature of club members at the Jan. 26-27 race meet in Tamworth - where the "pit" area is entirely accessible, children are encouraged to ask questions, and people can pet dogs with permission - it's difficult to see how such a family-centric endeavor has not become more widely embraced.

"It's not really a sport, it's a lifestyle," said Gretchen Karlson of Concord, Mass., who races strictly for fun in the sportsman divisions of four- and six-dog sprints.

She and her husband recently scaled back their racing kennel from 35 to nine dogs, now that their children are grown and Martha is recovering from knee surgery.

"To watch an animal do what it's bred for, it's very satisfying," she said.

Although Alaskan and Siberian Huskies have long been thought of as the iconic sled dogs, various European mixes, including Pointers and German short-hair crosses, now constitute racing teams. Karlson said good body structure, rugged feet, and an intense drive ("crazy to run") are what mushers look for in a sled dog.

Karlson said young pups "learn by osmosis" from older pack members, and are first hooked to a racing harness at 6 months of age.

"You don't push them," she said. "You take it easy and have fun."

Dogs race in teams from as small as one or two (known as "skijoring," when the musher is pulled on skis) up to an unlimited number in the open-class divisions (on the twisty Tamworth course, no one raced more than 12).

A typical team of six is made up of a pair of confident leaders in front, two versatile "point and swing" dogs in the middle, and a third tandem of blocky, burly "wheel" dogs closest to the sled.

In New England, most of the racing is sprinting, with the general rule being 1 mile per dog (eight-dog teams, for example, race 8-mile heats). Middle-distance racing can be anywhere from 30 to 120 miles with an overnight stop.

By contrast, the famous 1,150-mile Iditarod in Alaska is the ultimate long-distance challenge, requiring several arduous weeks in arctic conditions.

At a two-day meet like Tamworth, dogs race once per day, and cumulative time determines the winner in each division (racers are marked with livestock ink to ensure the same dogs race both days).

Drivers compete in "sportsman" or "pro" classes. Only pros can compete for prize money, but purses are so small at the club level that earning back a $40 registration fee is considered a big score.

Safety issues

The sled itself is traditionally made of white ash and costs between $800 and $1,000. Newer models made of high-tech composites go for five times as much. Regardless of the model, each sled has waxed runners on the bottom (shorter for control, longer for speed), and a snow anchor that wedges into the ice in case the driver has to stop midrace. Each sled must also have a basket to carry home a dog in the event of injury.

As in many sports, helmets are coming into vogue; they are mandatory for minors who race in the NESDC junior division.

Although sled racing does not leap to mind as an event fraught with danger, just about every musher hanging around Tamworth's pit row has a horror story to tell about sleds getting toppled and drivers getting dragged through the woods. Instinctively, the dogs just won't stop running.

Pro-class sprinter Mizzoni - whose daughter, Jackie, also races at the pro level - said she wiped out and separated her shoulder a few seasons back. Although it takes a bit of prodding from fellow drivers, Mizzoni acknowledges that at last year's Tamworth meet, she accidentally hooked her snow anchor into her calf, reluctantly went to the hospital to get stitched, and returned the same afternoon to compete in her remaining heats.

Chris Hayes, vice president for the NESDC, said animal welfare problems have not been an issue for his club because sled dog racers have no tolerance for negligence. Hayes said the only borderline issues he's ever encountered were instances in which finances made proper care a hardship, "and in that case, the mushing community will step up and absorb those dogs" into new homes.

Mizzoni, whose work as an animal control officer and a veterinary technician allows her a broad perspective on canine care, said what people don't realize is that before sled dogs ever make it to the races, they are screened to ensure that they have the physical ability and temperament to enjoy what they do. Dogs can race up to age 12 or 13, and those that don't show desire or ability retire as pets.

"You have to have well-cared-for dogs, or they're not going to run for you," Mizzoni said.

The controlled chaos all around Hayes and Mizzoni lends credence to their statements: Dogs returning from races are winded, but carry themselves with pride, tails wagging. Club members help each other out, rigging sleds and harnessing dogs for upcoming heats. By noon, cars of curious onlookers line Route 16 for a quarter-mile in either direction, and kennel owners are casually chatting with families, introducing their dogs, and explaining the sport.

"Kids naturally love dogs. Families like it," said Fran Plaisted of Orford, N.H., just prior to the first of her two winning runs in the 4-mile skijoring division.

"This lake will be jammed with kids playing in the snow by the end of the afternoon. I just think our society's so 'inside' now. Out here, at least you get away from TV and the video games."